You can edit $text in a rule to achieve a "pass-and-a-half" parsing. When you recognize a macrodef, store the key into a hash, with the value being the replacement string. Then, whenever you are looking for an identifier, also look first to see if it's one of the keys, and if so, prepend $text with the corresponding value and accept it.

I've been thinking about writing a column on that, but haven't finished. I saw a good example of that in theDamian's class notes though.

-- Randal L. Schwartz, Perl hacker

update: The file demo_cpp.pl in the Parse::RecDescent distro has a good example of mangling $text.

In reply to •Re: Macros in a RecDescent grammar by merlyn
in thread Macros in a RecDescent grammar by mush4brains

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